[PATCH bisected regression] sched: rebuild sched domains at suspend/resume

[Konstantin Khlebnikov <khlebnikov@openvz.org>]

This is fix for suspend/resume regression introduced in commit 8f2f748b0656
("CPU hotplug, cpusets, suspend: Don't touch cpusets during suspend/resume")
Without this patch suspend always hangs on my thinkpad x220 (2 x CPU * HT).

cpuset_update_active_cpus() not only juggles with bits in cpusets,
it also calls sched-domains rebuilding after all.

This patch restores sched-domain rebuilds, as it was before that commit.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
---
 kernel/sched/core.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 9995eb0..0fb7406 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6732,6 +6732,10 @@ static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
 	case CPU_DOWN_FAILED:
 		cpuset_update_active_cpus();
 		return NOTIFY_OK;
+	case CPU_ONLINE_FROZEN:
+	case CPU_DOWN_FAILED_FROZEN:
+		rebuild_sched_domains();
+		return NOTIFY_OK;
 	default:
 		return NOTIFY_DONE;
 	}
@@ -6744,6 +6748,9 @@ static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
 	case CPU_DOWN_PREPARE:
 		cpuset_update_active_cpus();
 		return NOTIFY_OK;
+	case CPU_DOWN_PREPARE_FROZEN:
+		rebuild_sched_domains();
+		return NOTIFY_OK;
 	default:
 		return NOTIFY_DONE;
 	}